The sender's email address remains a good indicator of whether an email is spam or not. By default, it's not intuitive in Microsoft Outlook Desktop to expand the view to include a column that displays the specific email address instead of the name. Microsoft hasn't yet implemented this feature as a simple option, but it can be added to the classic Windows version of Outlook using built-in tools.
The following steps show the sender's email address in plain text:
- View > View Settings > Columns > New Column…
- Name: From Email
- Type: Formula
- Formula: [SearchFromEmail]

The new column can then be moved to the desired position using drag & drop:

Finally, we apply this view to all folders:
- Change view > Apply current view to other email folders
- Select all
- Apply view to subfolders

The procedure is quick, requires no add-ins, and increases everyday security, especially for inexperienced users. The Outlook for Windows and outlook.com interfaces currently offer neither field selection nor formulas. One more reason why Outlook from Microsoft 365 (now also called "classic"!) will remain irreplaceable for years to come, especially in professional corporate environments.